#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>

int main(void){
	if(lseek(STDIN_FILENO, 0, SEEK_CUR) == -1)
		printf("can't seek\n");
	else
		printf("seek ok\n");

	exit(0);
}
